Needle threading devices



Dec. 10, 1957 E. cLAUss ETAL NEEDLE TI-IREADQING DEVICES 2 Sheets-Sheet 1 Filed June 3, 1954 6 2. 10, 1957 E, c uss ETAL 2,815,727

NEEDLE THREADIN DEVICES Filed June 3, 1954 2 Sheets-Sheet 2 INVENTORS [M/L AND BY fif/VNA/V/V Z/lV/f 4% u Agar/w- United States Patent NEEDLE THREADING DEVICES Emil Clauss and Hermann Zink, Kaiserslautern, Germany, assignors to G. M. Pfalf A.-G., Kaiserslautern, Pfalz, Germany Application June 3, 1954, Serial No. 434,202

Claims priority, application Germany June 8, 1953 6 Claims. (Cl. 112-225) The invention relates to an arrangement for mechanically operating needle threading devices adapted to facili- I and 420,169, new Patent No. 2,739,553, dated March 27, 1956, owned by the same assignee as the present application.

With the numerous known arrangements proposed for mechanical threading which employ a hook for guiding the thread through the eye of the needle, the placing of the thread upon the hook which projects from the eye is effected almost exclusively by hand. In view of the necessarily small dimensions of the. hooks and in view of the resistance of the thread which may be caused by hard twist, glazing and tight winding upon the thread rolls, the placing causes difliculties and causes losses in time. Also the arrangement of edges along which the thread may be guided upon the hook does not provide for any effective solution of the problem, particularly if one hand is required for the operation of the hook,

so that merely the other hand is available for the placing operation.

It is the object of the invention to provide an arrangement, which makes it possible to place the thread, which may be of any desired thickness and quality, safely upon the hook and with slight tension, and to effect at the same time the movement of the hook. For the solution of this problem means are provided at the lower end of the hook guiding bar which hold the thread, which has been inserted, so that it may be steady for the actual threading operation. The end of the thread is introduced into the clamping means, whereupon the threading hook is moved through the eye and the thread placed across the hook and held with the hand. Provision of the thread clamp on the guiding bar not only makes the operation very simple, but it is also possible to aid the tensioning of the thread by movement of the guiding bar, while it is possible to keep the tension low.

One embodiment which is feasible provides for a. disk which is under the pressure of a spring, and which is secured to the guiding bar in the direction of the longitudinal axis thereof. In another feasible embodiment of the invention a helical spring is secured to the lower end of the guiding bar. Finally it is also possible to utilize a leaf spring mounted on the guiding bar.

In the accompanying drawings embodiments of the new thread clamp are illustrated by way of example, where Fig. 1 shows a partial view of the operative position of the threading arrangement having thread clamping means constituted by a disk;

Fig. 2 shows the essential parts of the clamp in accordance with Fig. 1;

Fig. 3 shows in perspective view another embodiment 2,815,727 Patented Dec. 10, 1957 of the clamping means where the clamp member of the guiding bar is provided with a spiral spring;

Fig. 4 shows a third embodiment where the clamp of the guiding bar is provided with a leaf spring;

Fig. 5 is a view of a machine head with the cover in opened position to expose one of the mechanisms relied on for the operation of the threading hook, and

Fig. 6 is a perspective view illustrating on an enlarged scale the manner in which the thread is placed upon the hook.

At the lower end of the hook guiding bar 1 is secured the clamp member or hook support 2 to which the book 3 is fastened by means of a screw or the like. A disk 4 is secured to the clamp member 2 by means of a screw 5 with a spring 6 therebetween.

.In the embodiment according to Fig. 3, a helical spring 7 is secured at one of its ends to the clamp member 2 by means of a screw 8.

In the embodiment according to Fig. 4 a leaf spring 9 is secured to the outer side of the clamp member 2 by means of a screw 10.

The thread which is to be inserted is manually located in the thread clamp 2 while the threading device is in position of rest. Depending on the particular embodiment it is located either between the disk 4 and the clamp member 2 (Figs. 1 and 2), or between any two turns of the helical spring (Fig. 3), or between the leaf spring 9 and the clamp member 2 (Fig. 4). V

With the cover of the machine head in closed position operating lever 11 of the threading arrangement is now manipulated downwardly with one hand. The elongated slot 11a of the operating lever is in engagement with pin 12 on a sliding member 12a provided on the guiding bar 1. Pin 12 slides in slot 11a and the sliding member with the guiding bar 1, clamp member 2 and disk 4 of the thread holding device are moved downwardly until the guiding bar engages an abutment at the level where hook 3 is in horizontal alignment with needle eye 14. Further pressure on lever 11 causes rotational movement of the guiding bar as a result of pin 13 sliding in its associated slot 13a. Rotation of the guiding bar then causes the hook 3 to enter the needle eye 14 in a manner indicated in Fig. 4. The downward and rotational movement of guiding bar 1, clamp member 2 and disk 4 of the thread holding device places the thread clamped by disk 4 adjacent the eye of the needle.

After the hook has entered the needle eye 14 the free end of the thread which is clamped in position on the clamp member 2 is placed with the other hand over the hook and held there. This results in the thread being securely placed on the hook in the correct position. The subsequent return movement of the hook causes the thread to be pulled out of the thread clamp and the loop formed behind the needle eye is pulled up. This operation can be facilitated by the hand holding the thread yielding slightly until the hook has backed out of the eye.

The invention, while described with reference to the specific embodiments of needle threading constructions is not dependent on any particular type of threading device but it can be utilized with devices operating with a simple operating movement as well as devices having a composite operating movement.

We claim:

1. In combination with a mechanically operated needle threading device for a sewing machine including a needle bar and a hook adapted to pull a thread through the eye of the needle and carried by a hook support on a guide bar extending parallel to and movable parallel to the needle bar and to the needle and rotatable about its longitudinal axis, a thread holding device including a clamping member secured to the lower end of said hook support and movable therewith, said clamping member being ormer.-

n eic fiect a clamping r tionroaaport onrotthethread thereby supporting the thread laterally of the eye of the needle preparatory tothe threading operation.

' 2. Incombination.withlamechaaica ly Operated nee le threading device ion a sewing rnachineincluding aneedle bar and awhook adapted tot-pull ia thread through the eye of thehneedle and carriedby a hoolg suppoigt-on, a guide-barextendingparallel to and movableparallel to the needle bar and to the needle and rotatable about'its longitudinahaxis, a thread holding device incl-uding a clamping membersecurcd; to thelower end of said hook supportandmovahle therewith; saidclamping member including a spring biased disk and being operable-to effect a-clamping actionpn a portion of the thread thereby supporting..the thread laterally of. the-eye of the needle Preparatory toth th ding Ope a ion.

3..- In combination wither-mechanically operated-needle threading device for a sewing machine including a needle bar. and-a hook adapted to pull a: read th o g t e ev of 1111c needle and carrie y a; ho k tsupno t nya sni e bar extending parallel to and movable parallel tothe needle banan othe n dlela drr ta ableabou its u inataxiaa threadih di gu e icezi clu in a c amp n member secured to the lower end of said hoplc rsupport and mova letherewith, said l mping mem er be n fined bv h icalspri g sec red r dsaidhwksupp n and being operable to efiect a clamping action on a portionof-thethread thereby supporting the thread laterally oftheeye of the needle preparatory to the thr eading operation.

4. In combination with a mechanically operated needle threadingdevice for a sewing machineinch ding a'needle bananda hookadapted to pull a thread through the eye of the needle and carried by a hook, support on a guide bar-extendingparallel-to and movable parallel to the. needlebar-and to the needle and rotatable about its longitudinal axis, a thread holdinggdevice including a clamping membersecured to the lower endtof said hook supportand movable therewith, said clamping member being defined by a leaf spring and being operable" toeffect 4 a..c1amn aaa2 i9a9n-aliga ion 923 .9 hrea t e upporting the thread laterally of the eye of the needle preparatory to the threading operation.

5. In combination with a mechanically operated needle threading device for a sewing machine including a needle bar and a hook adapted tolpull a thread through the eye of the :needle and..carr;ie d-.by a hook support on a guide bar extending parallel to and movable parallel to the needle .bar .andr-sto the :nwdleand. rotatablev about. its longitudinal axis; a-thread holding device including a clamping member secured to the lower end of said hook support and, moyahleJherewith, said clamping member beingoperable to effect a clamping action on a portion of the thread -thereby-supporting the thread laterally of the eye of the needle preparatory to the threading operation, adjacent to and at' the level of the eye of the needle.

6. In combination with a mechanically operated needle hreadin dey s -supn r sd t he cw gi hine q ethe he-redr socabk eed ea omprising a u dei arh ioya lez a le to i e d e a and rotatable about; its longitudinal axis and .a needle r e dinal qqkima ne 9.9 s pp t. on s i e. ant r m v mea hr u hzth eyep a ee e pporte 1 sa dneed e.bar .a t read h ldi d e m t dn S i l Q L5UPPQ $Jb 19W al JL QQ'k pr si t ead n aginge l ments: pera let ra p. d hold a Portion of the thread substantially horizontally while an adjacent portionvof thenthreadis.placed in said hook and pulled through the eye .of: the needle.

References; .Cited-s-in the; file of this patent UNITED STATES PATENTS 

